Effects of Extracts of Posterior Lobe of Pituitary 91 



before. This galactagogue action of pituitary extract was confirmed in 

 lactating cats by Mackenzie and myself. The method we employed con- 

 sisted in canalising or in- 

 cising the nipple of one 

 or two of the mammae so 

 as to allow any milk which 

 was secreted to run out. 

 The milk was conducted 

 to the side and registered 

 by allowing it to fall upon 

 an electrical drop recorder. 

 This modus operandi per- 

 mits the conditions of the 

 experiment to be con- 

 trolled and the results ac- 

 curately recorded. It can 

 in this way be shown that 

 even a very minute dose 

 of the pituitary autacoid 

 — whether the same hor- 

 mone as that which affects 

 the muscular tissue of the 

 blood-vessels and viscera, 

 cannot certainly be said — 

 will cause milk which has 

 accumulated in the gland 

 to be immediately poured 

 out (fig. 64), whilst a 

 somewhat larger dose will 

 produce complete empty- 

 ing of the alveoli. If the 

 nipple is not canalised 

 or incised, the resistance 

 which is afforded in the 

 passage through its ducts, 

 controlled as they are by 

 the plain muscle tissue 

 which abounds in the 

 nipple, does not permit 

 of this emptying, and no 

 actual outpouring of the 

 secretion takes place. If 

 tract is made in the arm 

 is felt in the 

 nipple 



an intramuscular injection of pituitary ex- 

 of a nursing woman, a feeling of tingling 

 in the mamma and a sensation of milk flowing towards the 

 is experienced like that which occurs when the child 



is put 



